An antenna array is a set of individual radiating elements, connected together to act as a single antenna, with a main beam or lobe. Conventionally, an antenna array may be referred to as a single antenna. Beam steering is the angular positioning of the main beam by controlling the amplitude and/or phase of the individual radiating elements. Beam steering allows the antenna array to transmit in a preferential direction, namely the direction of the main beam, or provide increased reception sensitivity to signals received from the direction of the main beam. In order to obtain a desired radiation pattern for the main beam, different phase modes of the antenna array may be combined.
Circuitry for beam steering may comprise individual phase-shifters and/or delay units for each of the individual radiating elements that make up the antenna array. As the target frequency range of an antenna increases, the ideal spacing of radiating elements in the array decreases. The reduced spacing between radiating elements may increase the complexity in implementing the beam steering circuitry and feed network used to connect to the radiating elements, as the beam steering circuitry and feed network generally do not scale with wavelength, unlike antenna structures.